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Idle 'no load' Consumption: Specs vs Your Personal Observation

1. Growatt SPF 12000T DVM MPV, low frequency inverter
2. 120/240 vac pure sine wave, split phase
3. 12 Kw
4. Idle/no load: 133 watts, measured 2.55 A @ 52.3 V
Spec: none published
5. No power-save/search mode in use, I'm always at least 500 watts
 
Keep coming back here so just thought I should add my own results:

1. Growatt SPF 12000T DVM MPV
2. 120/240 split phase
3. 12kW
4. Idle/no load: ~155W. Seeing .81 amps from each of my 4 48V batteries, but given my battery voltage is usually higher, we could probably say ~168W at 52V. Nothing connected except Growatt.
5. In power save mode, I see the current draw from the batteries drop to 0 for most of the time, with the pulses seeming to use a similar amount of power every 3 seconds. So maybe roughly a third but I can measure this better and edit this post. I never use this mode because often my loads are low enough (few LED lights, computer) that it shuts itself off. Super annoying. Also have a fridge that doesn't respond well to this, and I see pulsing from some of my bulbs so it doesn't seem good for the electronics.
 
Doing some initial testing on my inverter/battery setup I recently received...

1. Growatt SPF 3000 TL 48P. Advertises <50W no load power consumption.
2. 120V pure sine (parallel/split-phase capable)
3. 3kW
4. ~30W idle, based on observations today of a ~5% loss over ~9 hours on a 5.1kWh LifePower4. Low enough that the BMS does not register it as discharging. Need to run this test longer, but other testing I've done suggests it is indeed lower than the 40-50W+ some others have reported (maybe they had high ambient temps and high fan speeds?).
5. "Power saving mode" is disabled (it can shut its inverter off if it detects no load, but this also leads to not being able to get certain devices started without anything else running, e.g. devices with momentary or touch on/off switches)
 
corn18 said:
  1. Victron Multiplus II
  2. 120V
  3. 3000VA
  4. 20W (20W spec)
  5. Search mode is 8W
Click to expand...
I'm a bit confused by this idea of idle consumption. I understand if the unit is "on" that there would be draw but, if it is in the off position should there not be zero draw? Mine, thanks to @MisterSandals, has been found to be drawing 17-20W when in the off position. That just doesn't seem right.....
 
There will always be SOME amount of power draw unless you turn off the battery breaker switch.

This is because the internal auxiliary power supply powering the processor requires something to operate looking at the on/off switch and reporting or logging battery voltage data or whatever. This would account for OFF power consumption.

Same thing with cell phones waiting for your push of the on button.

boB
 
Exeltech XP1100 48 volt HF inverter
20 watt idle spec
11 watt idle after low idle kit installed
Verified with DVM and DC clamp meter.
 
Dzl said:
In this thread, I hope to consolidate personal observations/measurements on inverter standby consumption. Specifically whether your observations are inline with what is stated on the datasheet, along with anything else you consider relevant, interesting, good or bad. With time--if this thread gains traction--it could be a useful resource for those shopping for inverters, and help us calibrate our expectations.

At a minimum report (1) Make+Model (2) Voltage (3) Max continuous power (4) Observed/measured standby consumption compared to spec sheet (5) Indicate whether power save features are active or not

*Keep in mind, any individual datapoint (even when its your own experience) is just a datapoint, subject to measurement error, bias, etc, but with a handful of datapoints, we can begin to feel a bit more confident drawing conclusions/generalizations.
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Mine hasn’t been at idle in a long time but I seem to remember 60 watts?? So x 2 would be 120wattsx24 Hours = 2.8kw day.

Sol-Ark 12kw AIO HF
240vac
48vdc
9kw each from Battery
60 watt idle consumption
 
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Same on my Sol-Ark 12k. I measure 60W idle consumption.
Steve brings up some valid points but I am also wondering how relevant a one on one comparison can be without grouping them into categories like Grid tied and AIO etc.
A lot more stuff is happening with an AIO when it is idling.
You don’t get those 4-10ms reaction times to an outage unless a lot of circuitry is constantly monitoring the Grid and has everything ready.
 
SpongeboB Sinewave said:
There will always be SOME amount of power draw unless you turn off the battery breaker switch.

This is because the internal auxiliary power supply powering the processor requires something to operate looking at the on/off switch and reporting or logging battery voltage data or whatever. This would account for OFF power consumption.

Same thing with cell phones waiting for your push of the on button.

boB
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Interesting. It makes sense but, does 17-20w seem excessive? I'm not real good with my math on this stuff but, Mr. Sandals calculated it this way: 20W x 24hr = 480Wh (15% of battery!) That seems pretty significant.... The other parasitic draws (Watchmon, led lights on Blue Sea 120v panel, contactor, etc), seem to add up to about 3ish watts. I'm thinking I may pull the positive cable off the batteries to the MP, and then get a more solid sense of things but, all indications are from a clamp meter, and the shunt readings that the draw from the MP is real.
 
saggys said:
Exeltech XP1100 48 volt HF inverter

11 watt idle after low idle kit installed
Click to expand...
Question....@saggys.......I was under the impression that the low idle kit is a factory installed option...If not I would like to install on my XP1100 , details please
 
Tecnodave said:
Question....@saggys.......I was under the impression that the low idle kit is a factory installed option...If not I would like to install on my XP1100 , details please
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You can contact Exeltech and they will ship you a kit for about $30. It consists of a section of heat shrink and a ferrite rod that you attach across the output? inductor. They will send detailed instructions as well.
They also have a option 20 transfer switch so you can use grid or generator power, it is under addendum for XP1100 on their website.

I ordered that also but have not tested it yet, I think that was around $50.
 
lance said:
Interesting. It makes sense but, does 17-20w seem excessive? I'm not real good with my math on this stuff but, Mr. Sandals calculated it this way: 20W x 24hr = 480Wh (15% of battery!) That seems pretty significant.... The other parasitic draws (Watchmon, led lights on Blue Sea 120v panel, contactor, etc), seem to add up to about 3ish watts. I'm thinking I may pull the positive cable off the batteries to the MP, and then get a more solid sense of things but, all indications are from a clamp meter, and the shunt readings that the draw from the MP is real.
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20 watts or so is perfect if it is putting out 120 or 240 volts sine wave. Should be way less than that if it's not. If it is only an inverter then maybe two or three watts when it is turned off would be about right
 
Reliable 1500w 24v 250v 50hz & 2000w 24v 240v 50Hz, (not the newer WZRELB types) Switched on, no loads 12w & 15w, the 1500w uses 1610w at 1500w output, and the 2000w uses 2180w.
One more thing, the 2000w inverter shuts down at about 2100w, but the 1500w inverter will not shut down even at 2500w, they both have voltage sag/drop compensation, and even at 2500w it's still around 245v. Also, the 1500w inverter was modified by the seller to 250v output, and I paid extra for 2 stage slower speed quiet fans at lower power draw, not the on-off full power fans that are standard, now at around 1400w draw the fans run much slower speed. I am now thinking of changing the input 100a trip/breaker to say 60a, as I think they messed something up when they altered it.
And it's not worth all the hassle sending it back to China.
 
lance said:
Interesting. It makes sense but, does 17-20w seem excessive? I'm not real good with my math on this stuff but, Mr. Sandals calculated it this way: 20W x 24hr = 480Wh (15% of battery!) That seems pretty significant.... The other parasitic draws (Watchmon, led lights on Blue Sea 120v panel, contactor, etc), seem to add up to about 3ish watts. I'm thinking I may pull the positive cable off the batteries to the MP, and then get a more solid sense of things but, all indications are from a clamp meter, and the shunt readings that the draw from the MP is real.
Click to expand...

Per the datasheet:

1672092599147.png

20W is normal in the ON position. Should be dramatically less in "off"

Here is my VRM with the inverter in "charger only" mode as set by the inverter controls in VRM.

1672092778986.png

SoC and power are as reported by the Batrium. BMV-702 reports within 0.1A of the Batrium as well....

21W, and that's the Wireless AP, the MiniPC and the Batrium (very consistent with their power specs). The dual 48/5000 Quattros are pulling nothing.

Very curious to see the results with the power cable disconnected.
 
12 watts from the AIMS 3000W PSW inverter. (It's an inverter only, no charger).

It starts all the appliances including chop and even large beam saws without hesitation.

I can't imagine an inverter with a 100 plus watt idle draw.

I do have a question though. On those units with big draw, say 100 watts, if you put let's say a 100 watt load on the thing, does it then draw 200 watts or does it fall into its efficiency rating and draw maybe 110 watts (just throwing out a random number) with a 100 watt load?

An idling car is producing enough power to make the car move but staying still its getting 0 MPG....
 
I assume inverters with huge idle draws have very large transformers that as a result, have high capacitance?

I guess we can't be too harsh as grid ac transformers have to be filled with oil to stay cool and are obviously wasting power as well.
 
Checkthisout said:
I do have a question though. On those units with big draw, say 100 watts, if you put let's say a 100 watt load on the thing, does it then draw 200 watts or does it fall into its efficiency rating and draw maybe 110 watts (just throwing out a random number) with a 100 watt load?
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I have an old Dynamote Brutus Inverter that draws 96 watts at idle but at higher power levels the overall efficiency improves a lot, it‘s only at small loads or ideling that the 96 watt idle draw is a problem. Its effeincy is close to the big transformer Magnasine inverters at over 1 kw. It is rated 3200 watts but has a whopping 19,200 watt overload capability. It will start and run a larger motor than the Magnasine will, has a much bigger transformer and outweighs the Magnasine by a good 20 pounds, on par with the big Schneiders
 
sunshine_eggo said:
No. The typical Growatt, MPP solar, Voltronics, etc., are all lightweight HF inverters without heavy transformers, but have very high idle rates.
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What's the reason for the high idle draw with those units?

130 watts with some of those? That's a lot of heat being generated just because the switch is on.

Then again maybe it doesn't matter in relation to their output. Some guys are so sun-rich. ?
 
Tecnodave said:
I have an old Dynamote Brutus Inverter that draws 96 watts at idle but at higher power levels the overall efficiency improves a lot, it‘s only at small loads or ideling that the 96 watt idle draw is a problem. Its effeincy is close to the big transformer Magnasine inverters at over 1 kw. It is rated 3200 watts but has a whopping 19,200 watt overload capability. It will start and run a larger motor than the Magnasine will, has a much bigger transformer and outweighs the Magnasine by a good 20 pounds, on par with the big Schneiders
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Not to threadjack but maybe a little...was that company up in Shoreline? Their inverters were popular with the sailboat and yacht crowd?
 
I think that it was in N.E. Washington area, where a bunch of the really great inverter designers were. That was in the very early days of inverters along with the Trace.

There was another inverter company back then that predated both the Trace and the Brutus and the designer was a sailor. Forgot the name for the moment but if @SpongeboB Sinewave is here about he will recall that for sure.
 
Heart Interface is probably who you were thinking of. Heart Ackerman and Steve Johnston started Heart. Then about a year later, Steve started Trace Engineering with a few others. Those others also worked at Phase Linear (Bob Carver) in the very early 1970s which was the "seed" basically for MANY Seattle area companies, both audio and inverter. I was at PL for a while. Phase Linear used to wind their own power transformers, as they did at Trace etc... so they knew how to do that already when the inverters came about.

Dynamote was the only company not part of that group. They were located partly in Shoreline (Brian Faley) but I think the company was down near Fremont or Magnolia. Brian Faley and Milt Rice were two engineers there. We worked with both of them at Trace and Magnum. Unfortunately, Milt Rice passed away by his ultralight around 2000 while he was at Trace. That was a sad time.

I would say that those HF inverters from China etc. do not have great idle power loss because they do not know that it is greatly wanted. So they don't work hard to reduce the idle.

And, usually, if an inverter has a idle or "tare" loss of whatever watts, that will not go down when you add a load to it. It is possible though to a certain extent I guess, but I would not think it would be much. Efficiency certainly goes up when you load it down a lot because the idle power becomes less than the actual load. I mean, 100 watts of idle or 10 watts of idle power, the efficiency is still zero when unloaded. Or is it negative ? ?

boB
 
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